1. Field of the Invention
The present invention relates to an illuminating device for illuminating an object to be illuminated by a white light generated by using a light emitting diode. The present invention also relates to a liquid crystal display device having a liquid crystal panel and an illuminating device for illuminating the liquid crystal panel, and more particularly to a liquid crystal display device having an illuminating device for illuminating a liquid crystal panel by a white light generated by using a light emitting diode.
2. Description of Related Art
As a display provided for a television, a personal computer, a portable electronic device, etc., a thin light weight liquid crystal display has been widely used. The liquid crystal display has a liquid crystal panel for displaying an image, but the liquid crystal panel is not self-luminous. Therefore, the liquid crystal display has an illuminating device for illuminating the liquid crystal panel, such as a backlight device for illuminating the liquid crystal panel from its back surface.
As a light source used frequently in the backlight device, there is a cold cathode fluorescent lamp (hereinafter referred to as “CCFL”). However, since the CCFL uses mercury, when the backlight device is, for example, broken, there is a possibility of giving an adverse influence to an environment, due to flowing out of the mercury or the like.
Then, a backlight device using a light emitting diode (hereinafter referred to as “LED”) is proposed (refer, for example, Patent Document 1: Jpn. U.M. Appln. Publication No. 7-36347 and Patent Document 2: PCT Appln. Laid-Open Publication No. 2000-540458).